A comprehensive study of plasmonic mode hybridization in gold nanoparticle‐over‐mirror (NPoM) arrays
Abstract
Hybrid plasmonic systems that combine localized and propagative surface plasmons offer new opportunities for tunable light–matter interactions at the nanoscale. This paper provides the most comprehensive study to date of hybridization between gap localized surface plasmons (gap LSP) and diffraction‐mediated propagative surface plasmon polaritons (SPP) in arrays of gold nanodisks over a mirror, part of the larger class of nanoparticle‐over‐mirror (NPoM) devices. By systematically mapping the hybrid mode dispersion as a function of array geometry over a large parameter space, we extract the coupling strength via a coupled oscillator model and reveal its dependence on key structural parameters, with gap thickness identified as the primary tuning factor. The resulting hybrid modes enhance the optical quality factor by nearly fivefold compared to classical LSP while maintaining strong near‐field confinement, combining the advantages of their constituent modes. Dephasing times were measured with interferometric time‐resolved photoemission electron microscopy (ITR‐PEEM). Using a scalable lithography‐compatible NPoM architecture that minimizes the optical index mismatch between the dielectric between the nanodisks and the gap material (Al 2 O 3 ), we achieved the highest coupling strength (123 meV) and dephasing time range (23–50 fs) to date in NPoM arrays.
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BibTeX
@article{gherman2026comprehensive,
title = {{A comprehensive study of plasmonic mode hybridization in gold nanoparticle‐over‐mirror (NPoM) arrays}},
author = {Raphael Gherman and Sacha Schwarz and Jean‐françois Bryche and Guillaume Beaudin and Alex Currie and Pierre Levesque and François Fillion-Gourdeau and Steve Maclean and Dominique Drouin and Serge Ecoffey and Paul Charette},
journal = {Nanophotonics},
year = {2026},
month = oct,
doi = {10.1515/nanoph-2025-0437},
url = {https://hal.science/hal-05800324v1},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - A comprehensive study of plasmonic mode hybridization in gold nanoparticle‐over‐mirror (NPoM) arrays
AU - Raphael Gherman
AU - Sacha Schwarz
AU - Jean‐françois Bryche
AU - Guillaume Beaudin
AU - Alex Currie
AU - Pierre Levesque
AU - François Fillion-Gourdeau
AU - Steve Maclean
AU - Dominique Drouin
AU - Serge Ecoffey
AU - Paul Charette
PY - 2026
DA - 2026/10/15
JO - Nanophotonics
DO - 10.1515/nanoph-2025-0437
UR - https://hal.science/hal-05800324v1
AB - Hybrid plasmonic systems that combine localized and propagative surface plasmons offer new opportunities for tunable light–matter interactions at the nanoscale. This paper provides the most comprehensive study to date of hybridization between gap localized surface plasmons (gap LSP) and diffraction‐mediated propagative surface plasmon polaritons (SPP) in arrays of gold nanodisks over a mirror, part of the larger class of nanoparticle‐over‐mirror (NPoM) devices. By systematically mapping the hybrid mode dispersion as a function of array geometry over a large parameter space, we extract the coupling strength via a coupled oscillator model and reveal its dependence on key structural parameters, with gap thickness identified as the primary tuning factor. The resulting hybrid modes enhance the optical quality factor by nearly fivefold compared to classical LSP while maintaining strong near‐field confinement, combining the advantages of their constituent modes. Dephasing times were measured with interferometric time‐resolved photoemission electron microscopy (ITR‐PEEM). Using a scalable lithography‐compatible NPoM architecture that minimizes the optical index mismatch between the dielectric between the nanodisks and the gap material (Al 2 O 3 ), we achieved the highest coupling strength (123 meV) and dephasing time range (23–50 fs) to date in NPoM arrays.
SN - 2192-8614
ER -